The present invention relates generally to an apparatus for exercising and rehabilitating muscles and joints, and more particularly to such an apparatus in which squat procedures or maneuvers are utilized for exercising and developing muscles as well as the exercising and rehabilitation of muscles and joints associated with acute, chronic and post surgical leg, hip, and lower back pathologies.
Presently available exercise devices utilizing a myriad of different motions and procedures have been employed for exercising the muscles and joints of human beings. Some of these available exercise devices utilize squat-type maneuvers for the purpose of exercising and rehabilitating leg and lower back muscles. Of these devices employing squat-type maneuvers, it has been found that all but one previously known device require the user to undergo an unnatural squatting motion which limits the exercise and rehabilitation maneuvers to only certain groups of muscles and joints while at the same time placing an excessive load or strain on other muscles and joints. For example, substantial shear forces present at the knee that occur during unnatural squatting motions where the knee extends forwardly over the toes of the user are instrumental in causing retro-patellar crepitus and patellofemoral disease.
The exception to the known squat-type exercise devices that provides squatting motions which closely approximates natural squatting motions is described in U.S. Pat. No. 4,872,670, issued to Raymond L. Nichols and entitled "Apparatus For Squat Exercise."
This patented apparatus generally comprises a vertical back support mounted between a pair of parallelogram-type side assemblies which provide a pantographic-type motion to the back support. During this pantographic motion the back support remains vertically upright while following an arcuate path so as to allow the user to squat in a motion closely imitating the natural squat motion of the user. With the back support moving in a arcuate path with the back support vertically oriented, the knees are prevented from extending over the toes of the user which thereby inhibits the occurrence of substantial tibio-femoral shear forces on the patella and the tibia so as to obviate or at least significantly minimize the retro-patellar crepitus and patella-femoral disease problems as mentioned above. The arcuate motion of the seat of a back support while traveling the arcuate path also inhibits undesirable joint movement so as to minimize any lumbar stress which may occur during squat exercises.
The aforementioned patented squat exercise apparatus is particularly useful for providing knee rehabilitation meneuvers such as required for rehabilitating of the anterior-cruciate ligament. The use of this patented apparatus has also been found to be particularly valuable for the rehabilitation of leg, hip, and back muscles associated with acute, chronic, and post-surgical pathologies especially since the lumbar and thoracic spine stabilizations as well as critical tibio-femoral angles are easily controlled. On the other hand, such thoracic spine stabilizations and tibio-femoral angles were found to be difficult to control when using other previously known squat exercise machines. Further, the use of this patented apparatus by a user having a leg prothesis is advantageous for the exercise of lower back and any thigh muscles since the lower leg and the prothesis below the knee are maintained in an essentially vertical plane during the entire exercise regimen so as to prevent the aforementioned undesirable tibio-femoral stresses from occurring. The patented device is also adjustable to fit users of different physical statures while affording desirable squatting motions.
While the aforementioned patented apparatus utilizing squat exercise maneuvers provides many advantages such as listed above that are not believed to be achievable in other known squat-type exercise machines employing squat maneuvers and can be readily adjusted for utilization by users of various physical make-up and stature, there are several attendant shortcomings or drawbacks to the aforementioned patented apparatus due to its construction but not to its function in the areas of muscle and joint exercising and rehabilitation, which detract from the overall acceptability of the apparatus. For example, the aforementioned patented apparatus is of a relatively complex construction which requires the use of a pair of identically constructed parallelogram-type side assemblies for supporting the back support therebetween in order to provide the required pantographic motion. This double-side assembly necessitates that the dimensions of the apparatus, especially the width thereof, be relatively large to assure easy ingress and egress of the user to and from the back support-containing area between the side assemblies and to also assure that the user has sufficient maneuvering room between the side assemblies to assume a proper position against the vertically oriented back support. The width of the assembled apparatus required to achieve these goals is such that the apparatus will not fit through conventionally-sized doorways. Thus, it was found to be necessary to either use the patented apparatus in areas accessible through relatively large doorways, such as double doors, or by disassembling and subsequently reassembling the apparatus in areas accessible through conventionally-sized doorways. Another drawback of the patented apparatus is due to its weight in that when assembled as described in the aforementioned patent the weight of the apparatus is approximately 500 lbs. Thus, the weight and the size of the apparatus resulted in the apparatus being quite cumbersome and awkward for moving or shipping purposes. A still further shortcoming in the patented apparatus is due to the relatively high construction costs thereof which tend to detract from the acceptability of the patented apparatus in some facilities such as in the home.
The present invention is directed to a modification of the patented apparatus which, apart from the aforementioned and other shortcomings or drawbacks of the patented apparatus, functions in a manner substantially similar to that in the patented apparatus. Thus, the aforementioned patent is incorporated herein by reference.